This invention relates to a pattern recognition method and relates also to a pattern recognition device for use in carrying out the method.
A pattern recognition device is for recognizing an input pattern signal representative of first through P-th input patterns by selecting first through P-th recognized patterns from a plurality of reference patterns, where P represents a first integer which is greater than one. The device thereby produces a recognition result signal indicative of first through P-th output (or true) identifiers identifying the first through the P-th recognized patterns. The pattern recognition device is typically a character recognition device which deals with the input pattern signal representing first through P-th input character patterns as the first through the P-th input patterns.
In the manner which will later be described in more detail, a conventional character recognition device comprises a reference pattern memory, namely, a character dictionary memory, which memorizes a plurality of basic reference character patterns as the reference patterns and a plurality of memorized identifiers identifying the basic reference character patterns. The character dictionary memory further memorizes a plurality of additional or modified reference character patterns corresponding to the memorized identifiers. The additional character patterns are given by modifying the basic reference character patterns. Supplied with the input pattern signal, the conventional character recognition device compares each of the input character patterns with each of the basic and the additional reference character patterns, and searches, as a searched pattern, a particular one of the basic and the additional reference character patterns that has the lowest dissimilarity with the input character pattern under consideration. In other words, the particular one of the basic and the additional reference character patterns having the largest similarity with the input character pattern under consideration. The conventional character recognition device thereby produces one of the memorized identifiers that corresponds to the searched pattern.
It is, however, difficult to prepare the reference pattern memory which memorizes a great number of the additional reference character patterns into which the basic reference character patterns are modified. Therefore, it is difficult for the conventional character pattern recognition device to accurately recognize each of the input character patterns.